/inch {72 mul} def

/wedge
  { newpath
      0 0 moveto
      1 0 translate
      15 rotate
      0 15 sin translate
      0 0 15 sin -90 90 arc
    closepath
  } def

gsave
  4.25 inch 4.25 inch translate
  1.75 inch 1.75 inch scale
  0.02 setlinewidth
  2 1 13
   {
     13 div setgray
     gsave
       wedge
       gsave
         fill
       grestore
       0 setgray stroke
     grestore
     30 rotate
   } for

grestore
showpage

